1. Introduction . Carbon dots (CDs) have attracted a lot of attention from researchers due to their properties such as carbon-based, zero-dimensional, quasi-spherical nanoparticles with fluorescent properties and extremely small particle size (usually below 10?nm). Furthermore, it is often considered to be a combination of inorganic quantum dots and organic ligand materials and applied in the fields of biological, photovoltaic, light emitting diode, etc. [ 1 , 2 ]. Most solvents for the...